michael@107: #include <config.h>
michael@107: #include <stdio.h>
michael@107: #include <stdlib.h>
michael@107: #include <string.h> /* for memcmp() */
michael@107: #include <assert.h>
michael@107: 
michael@107: #include "types.h"  /* for byte and u32 typedefs */
michael@107: #include "g10lib.h"
michael@107: #include "cipher.h"
michael@107: 
michael@107: /* configuration stuff */
michael@107: #ifdef __alpha__
michael@107:   #define SIZEOF_UNSIGNED_LONG 8
michael@107: #else
michael@107:   #define SIZEOF_UNSIGNED_LONG 4
michael@107: #endif
michael@107: 
michael@107: #if defined(__mc68000__) || defined (__sparc__) || defined (__PPC__) \
michael@107:     || (defined(__mips__) && (defined(MIPSEB) || defined (__MIPSEB__)) ) \
michael@107:     || defined(__powerpc__) \
michael@107:     || defined(__hpux__) /* should be replaced by the Macro for the PA */
michael@107:   #define BIG_ENDIAN_HOST 1
michael@107: #else
michael@107:   #define LITTLE_ENDIAN_HOST 1
michael@107: #endif
michael@107: 
michael@107: #ifndef DIM
michael@107:   #define DIM(v) (sizeof(v)/sizeof((v)[0]))
michael@107:   #define DIMof(type,member)   DIM(((type *)0)->member)
michael@107: #endif
michael@107: 
michael@107: /* imports */
michael@107: void g10_log_fatal( const char *fmt, ... );
michael@107: 
michael@107: 
michael@107: /* local stuff */
michael@107: 
michael@107: #define FNCCAST_SETKEY(f)  ((int(*)(void*, byte*, unsigned))(f))
michael@107: #define FNCCAST_CRYPT(f)   ((void(*)(void*, byte*, byte*))(f))
michael@107: 
michael@107: #define IDEA_KEYSIZE 16
michael@107: #define IDEA_BLOCKSIZE 8
michael@107: #define IDEA_ROUNDS 8
michael@107: #define IDEA_KEYLEN (6*IDEA_ROUNDS+4)
michael@107: 
michael@107: typedef struct {
michael@107:     u16 ek[IDEA_KEYLEN];
michael@107:     u16 dk[IDEA_KEYLEN];
michael@107:     int have_dk;
michael@107: } IDEA_context;
michael@107: 
michael@107: static u16
michael@107: mul_inv( u16 x )
michael@107: {
michael@107:     u16 t0, t1;
michael@107:     u16 q, y;
michael@107: 
michael@107:     if( x < 2 )
michael@107: 	return x;
michael@107:     t1 = 0x10001L / x;
michael@107:     y =  0x10001L % x;
michael@107:     if( y == 1 )
michael@107: 	return (1-t1) & 0xffff;
michael@107: 
michael@107:     t0 = 1;
michael@107:     do {
michael@107: 	q = x / y;
michael@107: 	x = x % y;
michael@107: 	t0 += q * t1;
michael@107: 	if( x == 1 )
michael@107: 	    return t0;
michael@107: 	q = y / x;
michael@107: 	y = y % x;
michael@107: 	t1 += q * t0;
michael@107:     } while( y != 1 );
michael@107:     return (1-t1) & 0xffff;
michael@107: }
michael@107: 
michael@107: static void
michael@107: cipher( byte *outbuf, const byte *inbuf, u16 *key )
michael@107: {
michael@107:     u16 x1, x2, x3,x4, s2, s3;
michael@107:     u16 *in, *out;
michael@107:     int r = IDEA_ROUNDS;
michael@107:   #define MUL(x,y) \
michael@107: 	do {u16 _t16; u32 _t32; 		    \
michael@107: 	    if( (_t16 = (y)) ) {		    \
michael@107: 		if( (x = (x)&0xffff) ) {	    \
michael@107: 		    _t32 = (u32)x * _t16;	    \
michael@107: 		    x = _t32 & 0xffff;		    \
michael@107: 		    _t16 = _t32 >> 16;		    \
michael@107: 		    x = ((x)-_t16) + (x<_t16?1:0);  \
michael@107: 		}				    \
michael@107: 		else {				    \
michael@107: 		    x = 1 - _t16;		    \
michael@107: 		}				    \
michael@107: 	    }					    \
michael@107: 	    else {				    \
michael@107: 		x = 1 - x;			    \
michael@107: 	    }					    \
michael@107: 	} while(0)
michael@107: 
michael@107:     in = (u16*)inbuf;
michael@107:     x1 = *in++;
michael@107:     x2 = *in++;
michael@107:     x3 = *in++;
michael@107:     x4 = *in;
michael@107:   #ifdef LITTLE_ENDIAN_HOST
michael@107:     x1 = (x1>>8) | (x1<<8);
michael@107:     x2 = (x2>>8) | (x2<<8);
michael@107:     x3 = (x3>>8) | (x3<<8);
michael@107:     x4 = (x4>>8) | (x4<<8);
michael@107:   #endif
michael@107:     do {
michael@107: 	MUL(x1, *key++);
michael@107: 	x2 += *key++;
michael@107: 	x3 += *key++;
michael@107: 	MUL(x4, *key++ );
michael@107: 
michael@107: 	s3 = x3;
michael@107: 	x3 ^= x1;
michael@107: 	MUL(x3, *key++);
michael@107: 	s2 = x2;
michael@107: 	x2 ^=x4;
michael@107: 	x2 += x3;
michael@107: 	MUL(x2, *key++);
michael@107: 	x3 += x2;
michael@107: 
michael@107: 	x1 ^= x2;
michael@107: 	x4 ^= x3;
michael@107: 
michael@107: 	x2 ^= s3;
michael@107: 	x3 ^= s2;
michael@107:     } while( --r );
michael@107:     MUL(x1, *key++);
michael@107:     x3 += *key++;
michael@107:     x2 += *key++;
michael@107:     MUL(x4, *key);
michael@107: 
michael@107:     out = (u16*)outbuf;
michael@107:   #ifdef LITTLE_ENDIAN_HOST
michael@107:     *out++ = (x1>>8) | (x1<<8);
michael@107:     *out++ = (x3>>8) | (x3<<8);
michael@107:     *out++ = (x2>>8) | (x2<<8);
michael@107:     *out   = (x4>>8) | (x4<<8);
michael@107:   #else
michael@107:     *out++ = x1;
michael@107:     *out++ = x3;
michael@107:     *out++ = x2;
michael@107:     *out   = x4;
michael@107:   #endif
michael@107:   #undef MUL
michael@107: }
michael@107: 
michael@107: static void
michael@107: expand_key( const byte *userkey, u16 *ek )
michael@107: {
michael@107:     int i,j;
michael@107: 
michael@107:     for(j=0; j < 8; j++ ) {
michael@107: 	ek[j] = (*userkey << 8) + userkey[1];
michael@107: 	userkey += 2;
michael@107:     }
michael@107:     for(i=0; j < IDEA_KEYLEN; j++ ) {
michael@107: 	i++;
michael@107: 	ek[i+7] = ek[i&7] << 9 | ek[(i+1)&7] >> 7;
michael@107: 	ek += i & 8;
michael@107: 	i &= 7;
michael@107:     }
michael@107: }
michael@107: 
michael@107: static void
michael@107: invert_key( u16 *ek, u16 dk[IDEA_KEYLEN] )
michael@107: {
michael@107:     int i;
michael@107:     u16 t1, t2, t3;
michael@107:     u16 temp[IDEA_KEYLEN];
michael@107:     u16 *p = temp + IDEA_KEYLEN;
michael@107: 
michael@107:     t1 = mul_inv( *ek++ );
michael@107:     t2 = -*ek++;
michael@107:     t3 = -*ek++;
michael@107:     *--p = mul_inv( *ek++ );
michael@107:     *--p = t3;
michael@107:     *--p = t2;
michael@107:     *--p = t1;
michael@107: 
michael@107:     for(i=0; i < IDEA_ROUNDS-1; i++ ) {
michael@107: 	t1 = *ek++;
michael@107: 	*--p = *ek++;
michael@107: 	*--p = t1;
michael@107: 
michael@107: 	t1 = mul_inv( *ek++ );
michael@107: 	t2 = -*ek++;
michael@107: 	t3 = -*ek++;
michael@107: 	*--p = mul_inv( *ek++ );
michael@107: 	*--p = t2;
michael@107: 	*--p = t3;
michael@107: 	*--p = t1;
michael@107:     }
michael@107:     t1 = *ek++;
michael@107:     *--p = *ek++;
michael@107:     *--p = t1;
michael@107: 
michael@107:     t1 = mul_inv( *ek++ );
michael@107:     t2 = -*ek++;
michael@107:     t3 = -*ek++;
michael@107:     *--p = mul_inv( *ek++ );
michael@107:     *--p = t3;
michael@107:     *--p = t2;
michael@107:     *--p = t1;
michael@107:     memcpy(dk, temp, sizeof(temp) );
michael@107:     memset(temp, 0, sizeof(temp) );  /* burn temp */
michael@107: }
michael@107: 
michael@107: static int
michael@107: do_idea_setkey( IDEA_context *c, const byte *key, unsigned int keylen )
michael@107: {
michael@107:     assert(keylen == 16);
michael@107:     c->have_dk = 0;
michael@107:     expand_key( key, c->ek );
michael@107:     invert_key( c->ek, c->dk );
michael@107:     return 0;
michael@107: }
michael@107: 
michael@107: static gcry_err_code_t
michael@107: idea_setkey (void *context, const byte *key, unsigned int keylen)
michael@107: {
michael@107:   IDEA_context *ctx = context;
michael@107:   int rc = do_idea_setkey (ctx, key, keylen);
michael@107:   _gcry_burn_stack (23+6*sizeof(void*));
michael@107:   return rc;
michael@107: }
michael@107: 
michael@107: static void
michael@107: do_idea_encrypt( IDEA_context *c, byte *outbuf, const byte *inbuf )
michael@107: {
michael@107:     cipher( outbuf, inbuf, c->ek );
michael@107: }
michael@107: 
michael@107: static void
michael@107: idea_encrypt (void *context, byte *out, const byte *in)
michael@107: {
michael@107:   IDEA_context *ctx = context;
michael@107:   do_idea_encrypt (ctx, out, in);
michael@107:   _gcry_burn_stack (24+3*sizeof (void*));
michael@107: }
michael@107: 
michael@107: static void
michael@107: do_idea_decrypt( IDEA_context *c, byte *outbuf, const byte *inbuf )
michael@107: {
michael@107:     if( !c->have_dk ) {
michael@107:        c->have_dk = 1;
michael@107:        invert_key( c->ek, c->dk );
michael@107:     }
michael@107:     cipher( outbuf, inbuf, c->dk );
michael@107: }
michael@107: 
michael@107: static void
michael@107: idea_decrypt (void *context, byte *out, const byte *in)
michael@107: {
michael@107:   IDEA_context *ctx = context;
michael@107: 
michael@107:   do_idea_decrypt (ctx, out, in);
michael@107:   _gcry_burn_stack (24+3*sizeof (void*));
michael@107: }
michael@107: 
michael@107: gcry_cipher_spec_t _gcry_cipher_spec_idea =
michael@107: {
michael@107:     "IDEA", NULL, NULL, IDEA_BLOCKSIZE, 128, sizeof (IDEA_context),
michael@107:     idea_setkey, idea_encrypt, idea_decrypt,
michael@107: };